A sequential execution of life cycle stages is the most straightforward. As presented in System Life Cycle Process Models: Vee and System Life Cycle Process Models: Iterative , variants of the Vee model and the spiral model provide non-sequential models when practical considerations require a non-linear execution of life cycle stages. Building upon these two models, it is important to note that various types of complex systems require that the stages of the life cycle model be revisited as insight knowledge is gained, as well as when stakeholder requirements change.
The iterations may involve necessary changes in the processes and in the product or service system. Thus, within the context of the T stage model, various orderings of stage execution - reflecting forms of non-sequential stage ordering - can be conveniently described, as portrayed in Figure 5. Each pattern of stage execution involves iteration of the previous stages, perhaps with altered requirements for the processes or the system.
The heavy lines in Figure 5 denote the demarcation of the revisited end points. Three are iterative forms, for which several variants can be extracted:.
In all of the approaches it is wise to use modeling and simulation techniques and related tools to assist in understanding the effect of changes made in the complex systems being life cycle managed. These techniques are typically deployed in the earlier stages; however, they can be used in gaining insight into the potential problems and opportunities associated with the latter stages of utilization and maintenance for example, in understanding the required logistics and help-desk aspects.
Regardless of the order in which life cycle stages are executed, stakeholder requirements for the system, including changed requirements in each iteration, must be allocated into appropriate activities of the processes used in projects for various stages as well as to the properties of the elements of the product system or service system and their defined relationships. Ideally, the project management team should implement proven processes that will integrate the technical process models with the project management product models to manage any of the processes discussed earlier, including incremental and evolutionary development.
The processes shown are the project management flow, starting with the beginning of the development phase Forsberg, Mooz, and Cotterman , Boehm, B.
Lane, S. Koolmanojwong, and R. Turner forthcoming. Forsberg, K. Mooz, and H. Visualizing Project Management. Lawson, H. A Journey Through the Systems Landscape. London, UK: College Publications. Wired News Contributors. Accessed on September 11, Visualizing Project Management , 3rd ed. The incremental model is great for projects that have loosely-coupled parts and projects with complete and clear requirements.
The iterative development model develops a system through building small portions of all the features. This helps to meet initial scope quickly and release it for feedback. In the iterative model, you start off by implementing a small set of the software requirements. These are then enhanced iteratively in the evolving versions until the system is completed. This process model starts with part of the software, which is then implemented and reviewed to identify further requirements.
Like the incremental model, the iterative model allows you to see the results at the early stages of development. This makes it easy to identify and fix any functional or design flaws. It also makes it easier to manage risk and change requirements. The deadline and budget may change throughout the development process, especially for large complex projects. The iterative model is a good choice for large software that can be easily broken down into modules.
The Rapid Application Development RAD model is based on iterative development and prototyping with little planning involved. You develop functional modules in parallel for faster product delivery.
It involves the following phases:. The RAD concept focuses on gathering requirements using focus groups and workshops, reusing software components, and informal communication.
The RAD model accommodates changing requirements, reduces development time, and increases the reusability of components. But it can be complex to manage. Therefore, the RAD model is great for systems that need to be produced in a short time and have known requirements. The spiral model is a risk driven iterative software process model. The spiral model delivers projects in loops. You develop the concept in the first few cycles, and then it evolves into an implementation. Though this model is great for managing uncertainty, it can be difficult to have stable documentation.
The spiral model can be used for projects with unclear needs or projects still in research and development. The agile process model encourages continuous iterations of development and testing. Each incremental part is developed over an iteration, and each iteration is designed to be small and manageable so it can be completed within a few weeks.
Each iteration focuses on implementing a small set of features completely. It involves customers in the development process and minimizes documentation by using informal communication. It can also present challenges during transfers as there is very little documentation.
Agile is great for projects with changing requirements. Congratulations on making it to the end! I hope you now have a better understanding of what software models are and how you should use them. We covered the different process models and learned when to use each. Next, you should look at:. This includes web application software architecture, microservices, AWS, and design considerations.
Join a community of , monthly readers. A free, bi-monthly email with a roundup of Educative's top articles and coding tips. All rights reserved. What is a software process model? Top 7 models explained. Jan 04, - 9 min read. Maryam Sulemani. We will learn the following: What is a software process model? Background Citations. Methods Citations. Results Citations. Figures and Topics from this paper. Citation Type. Has PDF. Publication Type.
More Filters. View 1 excerpt, cites background. View 1 excerpt, cites methods. Phased model for component driven approach in software development lifecycle. Software development organizations follow some process when developing a software product. A key component of any software development is life cycle model, on which the process is based. The high … Expand. A flexible software process model. Notice of RetractionDevelopment and analysis of 3C-Model for software development lifecycle.
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